Polymeric compositions plasticized with 2, 2-dimethylalkyl esters of dibasic acids



United States Patent POLYMERIC COMPOSITIONS PLASTICIZED WITH 2,2DIMETHYLALKYL ESTERS 0F DIBASIC ACIDS Hugh J. Hagemeyer, Jr., and AldenE. Blood, Longview,

Tex., assignors to Eastman Kodak Company, Rochester, N.Y., a corporationof New Jersey No Drawing. Filed Nov. 15, 1965, Ser. No. 507,689

13 Claims. (Cl. 26031.8)

Thisapplication is a continuation in part of our application Ser. No.237, 295 filed Nov. 13, 1962, and now abandoned.

This invention relates to new plastic compositions and more particularlyto polymeric plastic compositions plasticized with 2,2-dimethylalkylesters of certain dibasic acids.

The invention is based on our discovery that the ester compounds havingthe formula:

wherein R represents a straight chain alkyl radical having 2 to 8 carbonatoms and X represents phenylene or (CH wherein n is a whole number from4 to 8, have unexpected advantages as plasticizers for a number ofdifferent types of polymers, including vinyl and poly- (methylmethacrylate) resins, and polyolefins, such as polypropylene, forexample.

The diester compounds used in preparing the novel polymeric plasticcompositions of the invention have superior hydrolytic, oxidative andheat stability and are compatible with a wide variety of dissimilarpolymeric materials. This compatibility enables their superiorproperties to be put to use and results in improved polymeric plasticcompositions.

The diester compounds appear to be especially useful in connection withpolyvinyl chloride resins and when incorporated therein in plasticizingamount yield plasticized polyvinyl chloride compositions havingexcellent allaround properties with superior tensile strengths,elongations and 100% modulus. The ability of the aforementioned estercompounds to :plasticize polypropylene results in polypropylenecompositions having a lower brittleness temperature.

The plasticizer compounds employed by us are diesters of certain dibasicacids which have been esterified by the primary monohydric alcoholsidentified hereinafter. The dibasic acids need not be esterified withonly one alcohol, 'but can be esterified with two differentalcohols-provided both alcohols satisfy the criteria set forthhereinafter.

The acids from which the diester plasticizer compounds are prepared aresaturated aliphatic dicarboxylic acids containing from 6 to 10 carbonatoms and benzene dicarboxylic acids. Adipic acid, pimelic acid, azelaicacid, suberic acid, sebacic acid, phthalic acid and isophthalic acid areexamples of suitable acids for the formation of the diester compounds ofthe invention.

The primary monohydric alcohols used in the preparation of the diesterplasticizer compounds have the formula:

OH; Rt 3-0HzoH a wherein R represents a straight chain alkyl radicalhaving 2 to 8 carbon atoms. These alcohols are characterized in that thecarbon atom in the ,8-position, i.e. the carbon atom adjacent to thecarbinol (CH OH) group, is a quaternary carbon atom,2,2-dimethy1-1-butanol, 2,2-di- 3,329,643 Patented July 4, 1967 icemethyl-l-pentanol, 2,2-dimethyl-1-hexanol, 2,2-dimethyll-octanol-and2,2-dimethyl-1-decanol are examples of the primary monohydric alcoholsused in the preparation of the diester plasticizer compounds.

Many of the diester plasticizer compounds of the invention are disclosedin French Patent 1,230,105. However, this patent does not disclose theirutility as plasticizers and so far as we are aware the prior artcontains no disclosure of our novel polymeric plastic compositions.

The diester plasticizer compounds are prepared using knownesterification procedures. The preparation of a number of theplasticizer compounds is disclosed in French Patent 1,230,105.

The following examples illustrate the invention.

Example 1.-Bis(2,2-dimethylbutyl) phthalate To a 3-liter, 3-neck flaskequipped with a Dean and Stark tube, condenser, and thermowell wereadded 1224 grams of 2,2-dimethylbutanol (12 moles), 592 grams ofphthalic anhydride (4 moles), ml. of benzene, and 3.5 grams of p-toluenesulfonic acid. The resulting mixture was heated at reflux removing thewater in the Dean and Stark tube as it formed. After a three-hour perioda total of 72 ml. of water was collected (theory 72 ml.). Distillationgave 1307 grams of bis(2,2-dimethylbutyl) phthalate (97.9 percent oftheory). The product boiled at 174.5 C./1 mm. The index of refraction(25 C./D) was 1.4874, and the specific gravity (20 C./20 C.) was 1.011.

Example 2.Bis(2,2-dimethylhexyl) phthalate Example 1 was repeated using1560 grams of 2,2-dimethyl-l-hexanol in place of 2,2-dimethyl-1-butanol.The bis(2,2-dirnethylhexyl) phthalate obtained had a boiling point of230 C./8 mm., a specific gravity of 0.9817 (20 C./20 C.) and an index ofrefraction of 1.4857 (25 C./D).

Example 3.-Bis(2,2-dimethyloctyl) phthalate This ester was prepared inaccordance with the procedure of Example 1 using an equivalent amount of2,2- dirnethyl-l-octanol in place of 2,2-dimethyl-1-butanol. Thebis(2,2-dimethyloctyl) phthalate obtained boiled at 239 C./3 mm., had aspecific gravity of 0.9663 (20 C./ 20 C.) and an index of refraction of1.4811 (25 C./D).

Example 4.Bis(2,2-dimethyldecyl) phthalate This ester was prepared inaccordance with the procedure of Example 1 using an equivalent amount of2,2- dimethyldecanol in place of 2,2-dimethyl-1-butanol. Thebis(2,2-dimethyldecyl) phthalate boiled at 242 C./0.3 mm. and had aspecific gravity of 0.9751 (20 C./20 C.).

Example 5.Bis(2,2-dimethyl0ctyl) adipate This ester was prepared inaccordance with the general procedure described in Example 1 usingequivalent amounts of 2,2-dimethyl-1-octanol (12 moles) and adipic acid(4 moles), in place of 2,2-dimethyl-1-butanol and phthalic anhydride,respectively. The bis(2,2-dimethyloctyl) adipate obtained boiled at 216C./4 mm.

Example 6.-Bis(2,2-dimethyl0ctyl) azelate This ester was prepared inaccordance with the gen- 1 eral procedure described in Example 1 usingequivalent Example 7.-Bzs(2,2-dimethyl0cryl) sebacate This ester wasprepared in accordance with the general procedure described in Example 1using equivalent bis (2,2-dimethylbutyl) adipate,bis(2,2-dimethylpentyl) ,adipate, bis(2,2-dimethylhexyl) adipate,bis(2,2-dimethyldecyl) adipate, bis(2,2-dimethylbutyl) azelate,bis(2,2-dimethylpentyl) azelate, bis(2,2-dimethylhexyl) azelate,bis(2,2-dimethyldecyl) azelate, bis(2,2-dimethylbutyl) sebacate,bis(2,2-dimethylpentyl) sebacate, bis(2,2-dimethylhexyl) sebacate,bis(2,2-dirnethyldecyl) sebacate, bis(2,2-dimethylpentyl) phthalate,bis(2,2-dimethylbutyl) pimelate, bis(2,2-dimethylpentyl) pimelate,bis(2,2-dimethylhexyl) pimelate, bis(2,2-dimethyloctyl) pirnelate,bis(2,2-dimethyldecyl) pimelate,

4' bis(2,2-dimethylbutyl) isophthalate, bis (2,2-dimethvylpentyl)isophthalate, bis(2,2-dirnethylhexyl) isophthalate,bis(2,2-dimethyloctyl) isothalate and bis(2,2-dimethyldecy1)isophthalate, for example.

Table I shows the improved resistance to hydrolysis exhibited bybis(2,2-dimethy1hexyl) phthalate. Improved resistance to hydrolysis ischaracteristic of the diester plasticizer compounds employed by us inthe novel useful plasticized compositions of our invention. Thisproperty makes the diester plasticizer compounds valuable inapplications Where hydrolytic conditions are met. The comparisons shownare for hydrolysis of the ester in 0.5 N potassium hydroxide-ethanolsolution.

TABLE I.COMPARATIVE HYDROLYTIC STABILITY (IN 0.5 N KOH/EtOI-I) PercentHydrolyzed 1'.n Ester 20 min. 40 min. 200 min.

Bis(2,2-dimethylhexy1) phthalate 19 36 80 Bis(2-ethylhexyl) phthalate.36 53 99 Bis(noctyl) phtha-late 53 74 100 Bis(u-n0nyl) plithalate 47 68V 100 Table II gives the physical properties of various diesterpl-asticizer compounds used in preparing the valuable plasticizedcompositions of our invention.

TABLE II.PI-IYSICAL PROPERTIES OF 2,2-DIMETHYLALKYL ESTERS bis2,2-dimethylbutyl) suberate, bis 2,2-dimethylpentyl) suberate,

Hydrol- Sp. Gr. (20 ysis (96 Ester B.P.* C.) N G./20 C.) Hours BoilingH20) Bis(2,2-dimethylbutyl) adipate 0.9391 0.15 Bis(2,2-climethy1hexyl)adipate 0. 9223 0.07 Bis(2 2-d1methyloctyl) adipate. 0.9100 0. 0Bis(2,2-dimethyldecyl) adipate 0.8950 0. 0

Bis(2,3dimethylbutyl) azelate. 0. 9279 0.08 Bis(2,2-dirnethylhcxyl)azelate- 0.9173 0. 0 Bis(2,2-dimethyloctyl) azelate 0.9061 0.0Bis(2,2-dimetliyldecyl) azelate. 0. 8997 0. 0

Bis(2,2-dimethylhexyl) sebacate 165/001 mm 1. 4488 0. 9134 0. 0Bis(2,2-dimethylocty1) sebacate 191/001 min. 1. 4456 0. 9000 0. 0

Bis(2,2-dimethylbutyl) phthalate. 266 1.4874 1.011 0, 0Bis(2,2-dimethylhexyl) phtha1ate 303 1. 4857 0. 9817 0. 0Bis(2,2-dimethylocty1) phthalate. 239/3 mm. 1. 4811 0. 9525 0. 0Bis(2,2-dimethyldecyl) phthalate 242/03 mm 1. 4749 0.9228 0. 0

*Boiling points are extrapolated to or are measured at 760 mm. unlessotherwise noted.

Tables III, IV and V give the properties of numerous bis2,2-dimethylhexyl) suberate, bis 2,2-dimethyloctyl) suberate, bis2,2-dimethyldecyl) suberate,

plasticized polyvinyl chloride compositions of our invention.Additionally, some .polyvinyl chloride compositions plasticized withknown polyvinyl chloride plasticizers are included for comparativepurposes.

TABLE III.-PROPERIIES OF POLYVINYL CHLORIDE PLASTIGIZED \VI'IH VARIOUSESTERS Bis(2,2- Bis(2,2- Bis(2,2- Bis( 2,2- (2,2-dimethy1- Bis(2,2-Di(2- Property dimcthylbutyl) dimcthylhexyl) dimethyloctyl)dimcthyldecyl) butyl-2,2- dimethylhcxyl) ethylhexyl) phthalatc phthalatephthalate phthalate dimethyloctyl) isophthalate phthalate phthalatc ZTensile Strength, p.s.i 3,000 3,050 2, 950 2, 700 3,100 3,050 3,100Ultimate Elongation, percent 310 315 330 300 340 325 375 100% Modulus,p.s.1 2,400 2, 050 1,850 2,400 1,850 2, 250 1,525 Elongation Retention,power 0 O 53 110 0 0 43 Tear Resistance, p.p.i 570 475 465 500 450 480385 Shore A Durometer Hardn 5 sec 91 87 89 90 S3 Soapy Water Extraction,percent, 0, 6 0. 3 0. 04 0. 01 1. 8 Heptarie Extraction, percent. 19 2426 28 23 Activated Carbon Loss, percent 6. 7 1. 0 0.3 0.1 5. 5Thickness, mils 8. 0 14 8v 5 l1 8. 5 Torsion Modulus, (1.:

35,000 p.s.i 3.0 -15 18 25 -20 135,000 p.s.i 1 20 40 AcceleratedWeathering:

H d 1/1 1/0 0/0 0/0 1/0 1/0 2/0 1/0 l/O 1/0 Exudation 0/0 1/0 1/0 1/00/0 1 Formulation: parts of polyvinyl chloride resin (Geon 101 EP) 2parts Ba-Od stabilizer, 2 parts epoxy stabilizer, 50 parts ofplasticizer (as indicated). Parts are expressed as parts by Weight. 1 Adiester having two different ester groups.

TABLE IV.PROPERTIES OF POLYVINYL CHLORIDE PLASTICIZED WITH2,2-DIMEIHYLALKANOL ESTERS OF DIBASIC ACIDS l Ester Bis(2,2-dimethylhexyl) adipate Tensile Strength, p.s.i 2, 650 UltimateElongation, percent 1, 250 100% Modulus, ps 1 385 Elongation Retentlon,percent- Tear Resistance, p.p.i 365 Shore A Durometer Hardness, sec- 80Soapy Water Extraction, percent 1. 8 Heptane Extraction, percent 25Activated Carbon Loss, percent- 6.0 Thickness, mils 11 Torsion Modulus,0.:

35,000 ps i -43 135,000 p.s.i 60 Accelerated Weathering:

Hand 1/0 Color 1/0 Exudation 1/0 1 Formulation: 100 Parts 01 indicated).Parts are expressed as parts by weight.

Bis (2,2-dimethyl- Bis(2,2-dimethyl- Bis (2,2-dimethyl-Bis(2,2-dimethylbutyl) azelate hexyl) azelate octyl) azelate hexyl)sebacate polyvinyl chloride resin (Geon 101 EP), 2 parts Ba-Cdstabilizer, 2 parts epoxy stabilizer, 50 parts of plasticizer (as TABLEV.COMPARATIVE PROPERTIES OF PLASTICIZED POLYVINYL CHLORIDE PlasticizersUsed 1 Tensile Elongation 100% Modulus (50 Phr. Strength (Percent) (psi)(1) Diisooctyl phthalate 3,025 290 2, 035 (2) Bis (2, 2'dimet hylliexyl)phthalate. 3,050 315 2,050 (3) Didecyl phthalate 2, 925 280 2, 105 (4)Bis(2,2-dimethyloctyl) phthalate. 2,950 330 1,850 (5). Diisooctyladipate 2, 735 325 1, 550 (6) Bis(2,2-dimethylhexyl) adipate 2, 650 3851,250 (7) Diisooctyl azelate 2, 015 255 1, 710 (8). Bis(2,2-Dimethylhexyl) azelatc 2, 700 430 1, 350

(9) Didecyl azelate (10) Bis(2,2-dimethyloctyl) azelate 2,050 240 1,400(11) Diisooctyl sebacate 2,220 220 1, 570 (12) Bis(2,2-dimethylhexyl)sebacateum 2,700 390 1, 300

The data on the plasticizers numbered (1), (3), (5), (7), (9) and (11)"Higher 0x0 Alcohols, Enjay Company, Inc., New Yor were taken from k 19,New York, 1957, p. 53.

Isooctyl alcohol is a mixture of 3, 4-dimethyl-1-hexanol 3,5-dimethyl-1-hexanol 4,5-dimethyl 30%, Inethylheptanols 15% and 5% ofunidentified alcohols.

mcthylheptanols, and there are no compounds with a quaternary carbonatom.

2 Phr. means parts by weight per 100 parts of resin. 3 Too incompatible.

TABLE VI.HEAT STABILITY OF PLASTICIZED PVCl WIRE COATINGS (WITHOUTBISPI'IENOL A) Retained Percent Elongation Plasticrzer Aft 7 days at 90C.

Diisodecyl phthalate 20 Bis(2, 2-dimethyloctyl) phthalate 56 1Composition: 100 parts Geon 101 EP (polyvinyl chloride), 7 parts clayfiller, 10 parts Dythal (dibasic lead phthalate), 60 parts plasticizer.Parts are by weight.

TABLE VII.PROPERTIES OF POLYPROPYLENE PLASTI- CIZED WITH 10% BY WEIGHTOF BIS(2,2-DIMETIIYLDEC- YL) ADIPATE As indicated hereinbefore, thediester plasticizers having the Formula I are compatible with a varietyof polymers. While they are especially useful in connection with poly-(vinyl chloride) polymers and While their utility and unique propertieshave been demonstrated with reference to poly(vinyl chloride) polymersthey have utility when used as plasticizers for other types of polymers.

Amongst the resins which may be plasticized may be mentioned vinylchloride homopolymers, and vinyl chloride copolymers containing a minorproportion of vinyl acetate, vinylidene chloride, alkyl maleates,acrylonitrile and alkyl acrylates, although this list is not to beregarded as limiting with regard to comonomers.

(3-methyl-1-heptanol and 5-methy1-1-heptanol) Decyl alcohol containspredominantly the isomeric tri- Ibid, p. 33.

The diester plasticizer compounds are compatible with poly (methylmethacrylate) resins. For example, 20 Weight percent (based on finalpolymer composition) of a phthalate ester made by reacting phthalicanhydride and an equal weight mixture of 2,2-dimethylbutanol and2,2-dimethylhexanol was blended with a 35' percent solution ofpoly(methyl methacrylate) (IV. 0.18) in isobutyl acetate. A pour filmwas prepared from the mixture and dried. The resulting film wasperfectly clear and had superior flexibility compared to theunplasticized material.

The diester compounds having the Formula I are also compatible withpolyolefins. For example, 10 Weight percent of bis(2,2-dimethy1decyl)adipate was blended with polypropylene using mill rolls. The plasticizerstruck in the polypropylene very rapidly to give a smooth compositionwith no evidence of incompatibility. As much as 20 percent ofbis(2,2-dimethyldecyl) phthalate has been blended into polypropylenewith no evidence of incompatibility. These compositions retain theirflexibility. Plasticizers such as the 0x0 derived diisooctyl phthalateor diisohexyl adipate show signs of incompatibility in polypropylene andthe compositions are brittle. The properties of thebis(2,2-dimethyldecyl) adipate-polypropylene composition are shown inTable VII compared to the original polypropylene.

The tabulations given hereinbefore show the superior properties of thediester plasticizers having the Formula I.

7 and a poly (vinyl chloride) wire coating composition plasticized withbis(2,2-dimethyloctyl) phthalate. The latter composition retains almost3 times more elongation.

A good poly(vinyl chloride) plasticizer should give the plasticizedpoly(vinyl chloride) composition a high tensile strength, a low modulusand a high elongation. These are three of the most important propertiesmeasured on plasticized compositions. These three properties arecompared in Table V between the diester compounds having the Formula Iand other branched chain esters derived from OX alcohols. Thecomparisons show that the diesters having the Formula I give highertensile strength (in all but one case), higher elongations in all casesand a lower 100% modulus in all but one case. The higher elongations andthe lower 100% modulus show the diester compounds having Formula I havegreater compatibility for poly- (vinyl chloride) resins than the estersderived from Oxo branched chain alcohols.

The amount of diester plasticizer incorporated with the polymer or resincan vary over a considerable range. The amount will vary with theparticular polymer or resin employed. Thus the compatibility of theplasticizer with the polymer to be plasticized is a factor. Asunderstood in the art, the plasticizer should be present in aplasticizing amount, that is, in an amount that imparts improvedproperties to the polymer. In general, the plasticizer should be presentin an amount sufficient to improve the flexibility of the polymer orresin and can vary from about 20 to about 150 parts by weight perhundred parts by weight of resin. Preferably, the proportion ofplasticizer is from about 40 to 100 parts per hundred parts of resin.These proportions apply particularly to po-ly(vinyl chloride) resins.The total amount of plasticizer within these ranges of proportion cancomprise one or more diesters having the Formula I or a mixture of sucha diester with one or more other types of plasticizers such asdi(2-ethylhexyl) phthalate, dibutyl phthalate, tricresyl phosphate andthe like.

Poly(vinyl chloride) compositions containing 50 percent by weight of thepoly(vinyl chloride) resin of a diester plasticizer having the Formula Iand wherein all or essentially all the plasticizer present is a diesterplasticizer having the Formula I are among the preferred compositions ofour invention.

The invention has been described in considerable detail with particularreference to certain preferred embodiments thereof, but it will beunderstood that variations and modifications can be effected within thespirit and scope of the invention as described hereinabove, and asdefined in the appended claims.

We claim:

1. A plasticized composition consisting essentially of a polymericplastic substance selected from the group consisting of vinyl chloridehomopolymers, copolymers of vinyl chloride and monoethylenicallyunsaturated monomers copolymerizable therewith and wherein themonoethylenically unsaturated monomer is in minor proportion,poly(-methyl methacrylate) resins, and polypropylene and a plasticizingamount of a plasticizer having the wherein R represents a straight chainalkyl radical having 2 to 8 carbon atoms and X represents a memberselected from the class consisting of phenylene and (CH wherein n is awhole number from 4 to 8.

2. A plasticized composition in accordance with claim 1 wherein thepolymeric plastic substance is selected from the group consisting ofvinyl chloride homopolymers and copolymers of vinyl chloride andmonoethylenically unsaturated monomers copolymerizable therewith andwherein the monoethylenically unsaturated monomer is in minor proportionand a plasticizing amount of a plasticizer having the formula set forthin claim 1.

3. The composition of claim 1 in which said plastic is polyproylene.

4. The composition of claim 1 in which said plastic ispolymethylmethacrylate.

5. A plasticized composition consisting essentially of a vinyl chloridehomopolymer and a plasticizing amount wherein R represents a straightchain alkyl radical having 2 to 8 carbon atoms and X represents a memberselected from the class consisting of phenylene and (CH wherein n is awhole number from 4 to 8.

6. A plasticized composition in accordance with claim 5 wherein theamount of plasticizer present is about 20 to about by weight of thevinyl chloride homopolymer.

7. A plasticized composition in accordance with claim 5 wherein theplasticizer is his (2,2-dimethylhexyl) adipate.

8. A plasticized composition in accordance with claim 5 wherein theplasticizer is bis (2,2-dimethyloctyl) adipate.

9. A plasticized composition in accordance with claim 5 wherein theplasticizer is his (2,2-dimethyloctyl) azelate.

10. A plasticized composition in accordance with claim 5 wherein theplasticizer is bis (2,2-dimethyloctyl) phthalate.

11. A plasticized composition in accordance with claim 5 wherein theplasticizer is bis (2,2-dimethy1hexyl) phthalate.

12. A plasticized composition in accordance with claim 5 wherein theplasticizer is a diester of (a) a saturated aliphatic dicarboxylic acidcontaining from 6 to 10 carbon atoms and (b) a saturated 2,2-dimethylalkanol containing from 6 to 12 carbon atoms.

13. A plasticized composition in accordance with claim 5 wherein theplasticizer is a diester of (a) phthalic acid and (b) a saturated2,2-dimethyl alkanol containing from 6 to 12 carbon atoms.

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FOREIGN PATENTS 1,230,105 9/1960 France.

ALEXANDER H. BRODMERKEL, Primary Examiner.

I. H. WOO, Assistant Examiner.

1. A PLASTICIZED COMPOSITION CONSISTING ESSENTIALLY OF A POLYMERICPLASTIC SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF VINYL CHLORIDEHOMOPOLYMERS, COPOLYMERS OF VINYL CHLORIDE AND MONOETHYLENICALLYUNSATURATED MONOMERS COPOLYMERIZABLE THEREWITH AND WHEREIN THEMONOETHYLENICALLY UNSATURATED MONOMER IS IN MINOR PROPORTION,POLY(METHYL METHACRYLATE) RESINS, AND POLYPROPYLENE AND A PLASTICIZINGAMOUNT OF A PLASTICIZER HAVING THE FORMULA: